According to William Gilbert Charge is something possessed by material objects that make it possible for them to expert electrical force and to respond to electrical force.

  • me = 9.10940 × 10-31 kg
  • mp = 1.67262 × 10-27 kg
  • mn = 1.67493 × 10-27 kg

An electron repels another electron at a distance of 1 cm with a force = 2.3 × 10-24 N. this force is called electric force.

The electrons must have some additional property [other than their mass], which is responsible for the electric force between them. This additional property of electrons, which gives rise to electric force between 2 electrons, is called electric charge. Just as masses are responsible for the gravitational force, charges are responsible for electric force.

two protons placed at a distance of 1 cm also repel each other with the same force = 2.3 × 10-24 N. it show that protons also have charges which in magnitude, must be equal to charge on electron. Two neutrons placed at a distance of 1cm attract each other with a force = 1.9 × 10-60 N, which is the gravitational force due to their masses.